using NUnit.Framework;

using Python.Runtime;

using System.Linq;
using System.Reflection;

namespace Python.EmbeddingTest
{
    public class TestOperator
    {
        [OneTimeSetUp]
        public void SetUp()
        {
            PythonEngine.Initialize();
        }

        [OneTimeTearDown]
        public void Dispose()
        {
            PythonEngine.Shutdown();
        }

        public class OperableObject
        {
            public int Num { get; set; }

            public override int GetHashCode()
            {
                return unchecked(159832395 + Num.GetHashCode());
            }

            public override bool Equals(object obj)
            {
                return obj is OperableObject @object &&
                       Num == @object.Num;
            }

            public OperableObject(int num)
            {
                Num = num;
            }

            public static OperableObject operator ~(OperableObject a)
            {
                return new OperableObject(~a.Num);
            }

            public static OperableObject operator +(OperableObject a)
            {
                return new OperableObject(+a.Num);
            }

            public static OperableObject operator -(OperableObject a)
            {
                return new OperableObject(-a.Num);
            }

            public static OperableObject operator +(int a, OperableObject b)
            {
                return new OperableObject(a + b.Num);
            }
            public static OperableObject operator +(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num + b.Num);
            }
            public static OperableObject operator +(OperableObject a, int b)
            {
                return new OperableObject(a.Num + b);
            }

            public static OperableObject operator -(int a, OperableObject b)
            {
                return new OperableObject(a - b.Num);
            }
            public static OperableObject operator -(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num - b.Num);
            }
            public static OperableObject operator -(OperableObject a, int b)
            {
                return new OperableObject(a.Num - b);
            }

            public static OperableObject operator *(int a, OperableObject b)
            {
                return new OperableObject(a * b.Num);
            }
            public static OperableObject operator *(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num * b.Num);
            }
            public static OperableObject operator *(OperableObject a, int b)
            {
                return new OperableObject(a.Num * b);
            }

            public static OperableObject operator /(int a, OperableObject b)
            {
                return new OperableObject(a / b.Num);
            }
            public static OperableObject operator /(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num / b.Num);
            }
            public static OperableObject operator /(OperableObject a, int b)
            {
                return new OperableObject(a.Num / b);
            }

            public static OperableObject operator %(int a, OperableObject b)
            {
                return new OperableObject(a % b.Num);
            }
            public static OperableObject operator %(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num % b.Num);
            }
            public static OperableObject operator %(OperableObject a, int b)
            {
                return new OperableObject(a.Num % b);
            }

            public static OperableObject operator &(int a, OperableObject b)
            {
                return new OperableObject(a & b.Num);
            }
            public static OperableObject operator &(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num & b.Num);
            }
            public static OperableObject operator &(OperableObject a, int b)
            {
                return new OperableObject(a.Num & b);
            }

            public static OperableObject operator |(int a, OperableObject b)
            {
                return new OperableObject(a | b.Num);
            }
            public static OperableObject operator |(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num | b.Num);
            }
            public static OperableObject operator |(OperableObject a, int b)
            {
                return new OperableObject(a.Num | b);
            }

            public static OperableObject operator ^(int a, OperableObject b)
            {
                return new OperableObject(a ^ b.Num);
            }
            public static OperableObject operator ^(OperableObject a, OperableObject b)
            {
                return new OperableObject(a.Num ^ b.Num);
            }
            public static OperableObject operator ^(OperableObject a, int b)
            {
                return new OperableObject(a.Num ^ b);
            }

            public static bool operator ==(int a, OperableObject b)
            {
                return (a == b.Num);
            }
            public static bool operator ==(OperableObject a, OperableObject b)
            {
                return (a.Num == b.Num);
            }
            public static bool operator ==(OperableObject a, int b)
            {
                return (a.Num == b);
            }

            public static bool operator !=(int a, OperableObject b)
            {
                return (a != b.Num);
            }
            public static bool operator !=(OperableObject a, OperableObject b)
            {
                return (a.Num != b.Num);
            }
            public static bool operator !=(OperableObject a, int b)
            {
                return (a.Num != b);
            }

            public static bool operator = b);
            }

            public static bool operator >=(OperableObject a, PyObject b)
            {
                using (Py.GIL())
                {
                    // Assuming b is a tuple, take the first element.
                    int bNum = b[0].As();
                    return a.Num >= bNum;
                }
            }
            public static bool operator (OperableObject a, int b)
            {
                return (a.Num > b);
            }

            public static OperableObject operator > offset);
            }
        }

        [Test]
        public void SymmetricalOperatorOverloads()
        {
            string name = string.Format("{0}.{1}",
                typeof(OperableObject).DeclaringType.Name,
                typeof(OperableObject).Name);
            string module = MethodBase.GetCurrentMethod().DeclaringType.Namespace;

            PythonEngine.Exec($@"
from {module} import *
cls = {name}
a = cls(-2)
b = cls(10)
c = ~a
assert c.Num == ~a.Num

c = +a
assert c.Num == +a.Num

a = cls(2)
c = -a
assert c.Num == -a.Num

c = a + b
assert c.Num == a.Num + b.Num

c = a - b
assert c.Num == a.Num - b.Num

c = a * b
assert c.Num == a.Num * b.Num

c = a / b
assert c.Num == a.Num // b.Num

c = a % b
assert c.Num == a.Num % b.Num

c = a & b
assert c.Num == a.Num & b.Num

c = a | b
assert c.Num == a.Num | b.Num

c = a ^ b
assert c.Num == a.Num ^ b.Num

c = a == b
assert c == (a.Num == b.Num)

c = a != b
assert c == (a.Num != b.Num)

c = a = b.Num)

c = a < b
assert c == (a.Num < b.Num)

c = a > b
assert c == (a.Num > b.Num)
");
        }

        [Test]
        public void OperatorOverloadMissingArgument()
        {
            string name = string.Format("{0}.{1}",
                typeof(OperableObject).DeclaringType.Name,
                typeof(OperableObject).Name);
            string module = MethodBase.GetCurrentMethod().DeclaringType.Namespace;

            Assert.Throws(() =>
            PythonEngine.Exec($@"
from {module} import *
cls = {name}
a = cls(2)
b = cls(10)
a.op_Addition()
"));
        }

        [Test]
        public void ForwardOperatorOverloads()
        {
            string name = string.Format("{0}.{1}",
                typeof(OperableObject).DeclaringType.Name,
                typeof(OperableObject).Name);
            string module = MethodBase.GetCurrentMethod().DeclaringType.Namespace;

            PythonEngine.Exec($@"
from {module} import *
cls = {name}
a = cls(2)
b = 10
c = a + b
assert c.Num == a.Num + b

c = a - b
assert c.Num == a.Num - b

c = a * b
assert c.Num == a.Num * b

c = a / b
assert c.Num == a.Num // b

c = a % b
assert c.Num == a.Num % b

c = a & b
assert c.Num == a.Num & b

c = a | b
assert c.Num == a.Num | b

c = a ^ b
assert c.Num == a.Num ^ b

c = a == b
assert c == (a.Num == b)

c = a != b
assert c == (a.Num != b)

c = a = b)

c = a < b
assert c == (a.Num < b)

c = a > b
assert c == (a.Num > b)
");
        }

        [Test]
        public void TupleComparisonOperatorOverloads()
        {
                string name = string.Format("{0}.{1}",
                typeof(OperableObject).DeclaringType.Name,
                typeof(OperableObject).Name);
            string module = MethodBase.GetCurrentMethod().DeclaringType.Namespace;
                PythonEngine.Exec($@"
from {module} import *
cls = {name}
a = cls(2)
b = (1, 2)

c = a >= b
assert c == (a.Num >= b[0])

c = a = a.Num)

c = b  b.Num)
");

        }
        [Test]
        public void ShiftOperatorOverloads()
        {
            string name = string.Format("{0}.{1}",
                typeof(OperableObject).DeclaringType.Name,
                typeof(OperableObject).Name);
            string module = MethodBase.GetCurrentMethod().DeclaringType.Namespace;

            PythonEngine.Exec($@"
from {module} import *
cls = {name}
a = cls(2)
b = cls(10)

c = a  b.Num
assert c.Num == a.Num >> b.Num
");
        }
    }
}